The Environment Agency said the affected brook, in Riverside Park, had returned to normal when their investigators attended the scene on Monday, having received reports from members of the public regarding pollution two days earlier.A spokesman for the agency said: We have been out to look for any signs of this incident after we received a call at the weekend. The water is running clear in this brook and in nearby watercourses where there were reports of pollution last year. Whatever coloured the water at the weekend has obviously passed through without any obvious sign of damage to the environment. Elizabeth Simons was one of those who reported the incident to the agency on Saturday. She said: The pollution was first noticed by dog walkers at about 9am on Saturday in the same stream where, on several occasions over the last couple of years, brightly coloured dyes have appeared. There have also been several incidents of oil pollution in the same stream over a number of years I am told by the dog walkers. Ms Simons said heavy rain overnight Saturday meant much of the dye had been washed away in the River Great Ouse by Sunday morning. It is not known what caused the pollution on this occasion but the Hunts Post reported similar incidents in November and December 2017 which, at the time, were traced to an industrial estate in St Peters Road, Huntingdon. There was also a large quantity of oil dumped in the same stretch of water in April 2018. The Environment Agency spokesman added: We encourage people to always let us know when they see incidents they are concerned about as it helps us to gather information for various locations. Concerns can be reported to our incident hotline on 0800 80 70 60.